Split pin



F. J. FENICLE.

SPLIT PIN. APPLICATION FILED JUNE 3, 1920.

1,416,700. Y atented May23,1922" WIT/M55558 FRANK J. FENICLE, OF EAS'ION, PENNSYLVANIA.

SPLIT PIN.

Application filed June 3, 1920.

To all whom it may concern Be it known that I, FRANK J. FnNIoLu, a citizen of the United States, residing at Fasten, in the county of Northampton and State of Pennsylvania, have invented certain new and useful Improvements in Split Pins, of which the following is a specification.

The present invention relates to pins such as are ordinarily employed as hinge pins for articulators used by dentists and laboratory men in the setting up of teeth. It fre quently happens that such pins drop out of the articulator during one operation of set ting up teeth and it is the purpose of the present device to provide a pin which is not only easy to insert and pull out as a' plain pin would be but is in addition so constructed as to be prevented from falling out, thus constituting a great saver of time and annoyance.

A further object is to provide a pin which can be used on. any sized pin articulator and which is provided with a split portion so arranged and located as to automatically lock the pin in place while at the same time per mitting it to be readily removed without twisting or destroying the pin.

As an additional object it may be stated that the invention comprises a pin which may be not only used as above represented but which may also be substituted in place of the common cotter pin in a great many instances.

With the above and other objects in view which will become apparent as the description proceeds, the invention may be said generally to reside in the details of construction, combination and arrangement of parts as will be hereinafter more fully pointed out, reference being had to the drawings wherein Figure 1 is a view from the rear end of the articulator showing the hinge pin in place.

Figure 2 is a vertical longitudinal section theretlirough taken on line 2-2 of Fig ure 1.

Figure 3 is a top edge view of the pin showing detached from the articulator and Figure 4 is a longitudinal vertical section through the pin taken on line H of Figure 1.

Figure 5 is a detail of a modified form of the pin.

In the drawings, the device used by Specification of Letters Patent.

Patented tra 23, rose.

Serial No. 386,283.

dentists and laboratory men for the purpose of setting up teeth and known as the articulator is only partly illustrated, the numerals l and 2 respectively indicating the movable jaws which are each provided with the in wardly turned hinge'ears 3 and 4 designed to be fitted. together in a manner shown to advantage in Figure 1 of the drawings. Ordinarily a plain pin is inserted transversely of the spaced pairs of ears so as to complete the hinge joint and to provide a hearing or pivot for the movable jaws of the articulator. It frequently happens that this pin often falls out of the articulator during one operation of setting up teeth re sulting in the loss of time and much annoyance. To overcome this defect it is the purpose of the present invention to provide a pin of the type illustrated in the drawings and comprising a strip 5 of solid material, such as round or half round spring wire, one end of which may be looped upon it self to provide a head 6 as shown. The solid shank of the pin is then provided with a slot 7 formed inwardly of the terminal ends of the pin so as to have solid portions 8 and 9 respectively adjacent each end of the slot. The slot divides the intermediate portion of the shank into two elastic strips 10 and 11 designed to normally bulge slightly outwardly from the sides of the shank and yieldable inwardly, under stress. In using a pin of this type, it may be inserted in the usual manner through the hinge ears 3 and 4 of the articulator so that when it is properly in place as disclosed in Figure 1, the solid portions 8 and 9 form bearings of constant uniform diameter for the respective pair of cars of the articulator jaws while the strips 10 and 11 of the bearings are free to expand and thus increase the diameter of the shank so as to prevent the pin from working loose through the opening in the ears. It is to be noted that the expansion of the strip occurs at a point remote from the ears of the hinge so that there is no possibility of the pin tending to bind within the supporting opening, or otherwise interfering with the free manipu lation of the articulator jaws. As the pin is inserted through the opening the edges of the latter force the yieldable strips 10 and 11 inwardly towards each other until they have passed entirely through the opening and into the space between the ears where they are free to expand outwardly to their normal position, thus locking the pin in place and preventing it from falling out. The removal of the pin is accomplished simply by catching hold of the head 6 and withdrawing the pin, there being no necessity tor the employment of a pair of pliers or of twisting the pin out of shape as would be the case were a cotter pin employed.

In the modified form, the invention may he constructed with only a single elastic or springlocking finger 12 made integral with the shank and adapted to be yieldably pressed into the cutout 13 provided for its reception, this finger being normally adapted to be sprung outwardly from the side of the shank so as to provide a self-locking element after it has been inserted through an opening as in the manner previously described.

Although the invention has been described with reference to its use in connection with an articulator it is to be understood that it can also be readily adapted for other uses and in fact, be used to replace the old style cotter or split pin in a great many cases. A pin of this improved structure is as easy to insert and pull out as a plain pin and yet is self locking so that it cannot fall out of place, although readily removable when ever desired. 1

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is:

1. A pin including a shank having nonexpansible ends, and a resilient portion between said ends capable of expansion and contraction.

2. A pin including a shank having nonexpansible ends and a resilient portion between the ends being normally expanded laterally of the shank and capable of contraction to the same cross section of the shank.

3. A pin including a shank having nonexpansible ends, said shank being split between said ends to provide a resilient eX- pansible and contractible portion.

it. A pin including a shank having non-- expansibleends, said shank having a laterally projecting spring finger between its ends.

In testimony whereof I aflix my signature in presence of two Witnesses.

FRANK J. F ENICLE.

Witnesses HLLIAM A. TABLER, JOHN MYERS. 

